Question

A factory was started near a village. Suddenly villagers started feeling the presence of irritating vapours in the village and cases of headache, chest pain, cough, dryness of throat and breathing problems increased. Villagers blamed the emissions from the chimney of the factory for such problems. Explain what could have happened. Give chemical reactions for the support of your explanation.

Answer 1

The symptoms observed in the villagers show that oxides of nitrogen and sulphur must be coming out of the chimney. This is due to combustion of fossil fuels like coal, oil, natural gas, gasoline, etc. to produce high temperatures at which oxidation of atmospheric nitrogen takes place forming NO and NO₂:

\[\ce{N2 + O2 ⇌[1200 - 1750°C] 2NO; 2NO + O2 ⇌[1100°C] 2NO2}\]

SO₂ is produced due to combustion of sulphur-containing coal and fuel oil or roasting of sulphide ores like iron pyrites (FeS₂), copper pyrites (CuFeS₂), etc.

\[\ce{Cu2S + O2 -> 2Cu + SO2}\]